Device for vapor sterilization of articles having lumens

ABSTRACT

A method and device for enhancing the vapor sterilization of the lumen of medical instruments and like articles under reduced pressure. A vessel containing a small amount of a vaporizable liquid antimicrobial solution is attached to the lumen. The antimicrobial vaporizes and flows directly into the lumen of the article as the pressure is reduced for the sterilization cycle. Preferred embodiments illustrate a sealed chamber containing the antimicrobial and an opener for opening the chamber with the device already attached to the article. Preferably, the opener comprises a hollow spike. A ring between the opener and chamber must be removed prior to opening the chamber and removal of the ring destroys the ring so that it can not be replaced.

This is a continuation-in-part of application Ser. No. 08/120,303 filedSep. 13, 1993, which is a continuation of application Ser. No.07/864,151 filed Apr. 2, 1992, now abandoned, which is a continuation ofapplication Ser. No. 07/464,843 filed Jan. 16, 1990, now abandoned,which is a division of application Ser. No. 07/079,550 filed Jul. 30,1987, now U.S. Pat. No. 4,943,414, issued Jul. 24, 1990.

BACKGROUND OF INVENTION

1. Field of Invention

The invention relates to the vapor sterilization of articles such asmedical instruments having long narrow lumens therein, and moreparticularly, to a device for delivering a gaseous antimicrobialdirectly into the lumen of an article during the sterilization process.

2. Background Information

The need to sterilize articles such as medical instruments and othersfor use in the agriculture and fermentation industries is well known. Inrecent years, many methods of vapor sterilization have been developed.While these methods offer the advantage of being generally faster thansterilization by immersion in an antimicrobial solution, they sufferfrom one major disadvantage, namely the inability to sterilize theinterior of a long narrow tube in a short period of time. Thus, withregard to medical instruments such as endoscopes, the difficulty insterilizing the lumen can often negate the general advantage of usingvapor sterilization.

One way of overcoming the above disadvantage is set forth in U.S. Pat.Nos. 4,410,492 and 4,337,223. The apparatus described therein comprisesa sterilizing chamber with means for introducing an antimicrobial gasinto the chamber and circulating the gas within the chamber. Disposedwithin the chamber is a socket for receiving the tubular end of amedical instrument. The socket is connected to a valve and arecirculating pump and the antimicrobial gas is recirculated from thechamber through the lumen of the instrument. The commercial apparatusemploys ethylene oxide as the antimicrobial and requires a sterilizationtimes of about 3 hours for flexible endoscopes and about 2 hours for theshorter, rigid endoscopes. Ethylene oxide is a known toxic substance andthe process thereby experiences concomitant toxicity problems. Inaddition, the method and apparatus described in these references cannotbe used to sterilize an instrument within a sterile pack since one endof the instrument must be attached to the socket.

Thus there is a current need for an effective method to sterilizemedical instruments such as endoscopes in a reasonably short period oftime, preferably in one hour or less. The method and device of thepresent invention makes vapor sterilization of such instrumentspractical by delivering vapor directly to the interior of the lumen inthe endoscope, whether or not it is in a sterile pack.

SUMMARY OF THE INVENTION

The present invention comprises a method and device for providingantimicrobial vapor directly into the long narrow lumen of medicalinstruments and similar articles. The device and method are intended foruse with solution vapor sterilization procedures. In these procedures,the article is placed within a sterilization chamber, the pressure inthe chamber is reduced, and a liquid solution of antimicrobial agent isintroduced into the chamber where it vaporizes. Alternatively, anantimicrobial vapor may be introduced directly into the chamber afterthe pressure therein has been reduced. In either case, the instrument issterilized by exposure to the vapor or active species generated from itrather than by direct contact with a liquid antimicrobial. The proceduremay further involve the use of heat or, e.g., low pressure gas plasma toenhance the antimicrobial activity, reduce sterilization times, and/orremove residual any antimcrobial agent from the instrument.

In its simplest form, the device of the present invention comprises avessel containing a small amount of the antimicrobial solution, and ameans for connecting the vessel to the lumen of the instrument toprovide a source of antimicrobial vapor directly to the lumen during thevapor sterilization process. The device is placed on the instrumentprior to disposing the instrument in the sterilization chamber. As thepressure in the chamber is reduced, the antimicrobial solution containedin the vessel is vaporized and passes from the vessel into the lumen ofthe instrument.

With the use of the device and method of the present invention, vaporsterilization times for endoscopes can be reduced to one hour or less.In addition, the method and the device may be used to sterilizeendoscopes in a sterile pack since the device of the present inventionmay be attached to and packaged with the endoscope before the endoscopeis placed within the sterilization chamber. Upon opening of the pack,the device may be retrieved for re-use or preferably discarded with thepack.

The device and method of the present invention reduce sterilization timerequired for instruments having long narrow lumens therein. Reducedsterilization times are also achieved with the instruments encased in apackage designed to maintain sterility after the removal from thesterilized chamber. In addition, as antimicrobial vapor is provideddirectly into the lumen of the instrument, lower concentrations ofantimicrobial solutions may be used in the sterilizer, and this togetherwith the reduced sterilization times provides improved materialscompatibility with respect to both the instrument components and thepackaging or wrapping materials.

A device according to the inventions delivers an antimicrobial vapor toa lumen of an article during solution vapor sterilization. The devicecomprises a first member which comprises a vessel having an inner sealedchamber containing an antimicrobial solution and a wall forming at leasta portion of the chamber. A connector connects the vessel to the articlelumen. A second member connects to the first member in moveable relationthereto. The second member comprises an opening member whereby movementof the second member in a predetermined direction relative to the firstmember moves the opening member toward wall to open the wall and placethe chamber into fluid communication with the article lumen.

Preferably, the opening member opens the wall via penetration thereofand comprises a spike having a first end and a second end, and whereinthe first end faces the wall and comprises a sharpened tip. Preferably,a central lumen extends coaxially through the spike and communicateswith the connector whereby the vessel is placed into fluid communicationwith the article lumen through the spike lumen when the spike penetratesthe wall.

Preferably, the first and second members interconnect in telescopingrelationship with each other. A detent and surface on the opposingmembers preferably limits the degree to which the first and secondmembers can telescope apart.

To ease the breaching of the wall a threaded interconnection can beprovided between the first and second members wherein rotation of thefirst and second members relative to each other moves them together tobreach the wall. A tactile detent can be provided to let a user knowwhen the members are fully rotated together.

Preferably, a guard is disposed between abutting surfaces on the firstand second members to prevent the first and second members from movingtogether sufficiently to breach the wall. The guard preferably has acontrasting appearance to the first and second members whereby thepresence or absence of the guard can easily be visually determined. In apreferred form, the guard comprises a ring encircling the device betweenthe first and second members and is inelastic so that to remove the ringfrom between the first and second abutting surfaces it must be deformedbeyond its elastic limit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of the device, accordingto the present invention, attached to the end of a tube;

FIG. 2 is a perspective view of another embodiment of the device of thepresent invention, showing the end of the device for making a connectionto a tubular member;

FIG. 2A is a perspective view of a variation of the device of FIG. 2;

FIG. 3 is a plan view of another embodiment of a device of the presentinvention;

FIG. 3A is a variation of the device of FIG. 3;

FIG. 4 is a plot of sterilization time verses efficacy and showingenhanced efficacy of attaching an H₂ O₂ device to a lumen prior tosterilization;

FIG. 5 is an exploded view of a further embodiment of a device of thepresent invention;

FIG. 6 is an exploded view in section of the device of FIG. 5;

FIG. 7 is an end view of the opener of the device of FIG. 5;

FIG. 8 is a plan view in section of the assembled device of FIG. 5,prior to use;

FIG. 9 is a plan view in section of the assembled device of FIG. 5,during use;

FIG. 10 is a perspective disassembly view of a further embodiment of adevice of the present invention;

FIG. 11 is a plan view in section of the assembled device of FIG. 10,during use;

FIG. 12 is a close-up plan view of a distal portion of a capsule portionof the device of FIG. 10; and

FIG. 13 is a sectional view taken along lines 13-13 of FIG. 12.

DETAILED DESCRIPTION OF THE INVENTION

The method and device of the present invention relates to thesterilization of articles such as medical instruments having a longnarrow tube therein. The term instruments as used herein applies tomedical or surgical devices such as endoscopes, catheters, tubing, orsimilar instruments or articles having am internal lumen which ispreferably used in a sterile condition as in, for example, theagricultural or fermentation industries. The method and device of thepresent application show particular advantages in the solution vaporsterilization of lumens exceeding ten centimeters in length and havingan internal diameter of about 7 millimeters or less. As endoscopestypically have lumens with internal diameters of 1 to 4 millimeters andlengths of up to 1.5 meters or more for flexible endoscopes and at least45 centimeters for rigid endoscopes, the method and device of thepresent application have particular applicability to the sterilizationof these instruments. With the use of the device of the presentinvention, antimicrobial vapor is supplied directly to the lumen orinterior of the tube of the instrument during the vapor sterilizationprocess.

The antimicrobials used with the method and device of the presentinvention include solutions of glutaraldehyde, hydrogen peroxide,chlorine dioxide or other antimicrobials in an inert solvent, the onlyrequirement being that the solution be liquid at atmospheric pressureand a vapor at the temperature and pressure of the sterilizationprocess. Though the higher concentration solutions of antimicrobials aremore effective, problems with materials compatibility and shipping andhandling may arise at very high concentrations. For example, a 30% to50% solution of hydrogen peroxide in water is both very effective andpresents few shipping and handling problems, while higher concentrationsof up to 70% become increasingly more difficult and dangerous to handle.

In solution vapor sterilization, the procedure generally used is asfollows: The article to be sterilized is placed within the sterilizationchamber, the chamber is sealed, and a vacuum is drawn on the chamber toreduce the pressure to less than about 50 torr, and preferably to 20torr or less. An antimicrobial solution is then injected into thechamber where it vaporizes and contacts the exposed surfaces of article.The time necessary for total kill of specific microbial agents varieswith the type and concentration of antimicrobials present, and with thedegree of exposure to the microbial agent. Microbials disposed incracks, crevices or internal tubular structures are somewhat protectedfrom the antimicrobial agent and require more time for total kill thanmicrobials on the external surface of the article. Heat or highfrequency radiation may be used to increase the effectiveness of theantimicrobial and its penetration into remote areas of the instrument.

The device of the present invention comprises a vessel for containing asmall amount of antimicrobial solution, and a means for connecting thevessel directly to the lumen or the end of the tube of the article to besterilized. When the article with device containing antimicrobialsolution is disposed in the sterilization chamber and a vacuum drawn onthe chamber, antimicrobial vapor generated from the solution within thevessel flows directly into the lumen.

The effectiveness of the method and device of the present invention wasdemonstrated by the following experiments:

50 inch (127 centimeters) lengths of Tygon tubing having a 2 millimeterinside diameter were used to simulate an endoscope in the sterilizationtest. A paper strip (2 mm×13 mm) containing approximately 2.0×10⁶Bacillus subtilis (var. globigii) spores was placed in each tubeequidistant from each end. A syringe containing 0.05 milliliters of 10%by weight hydrogen peroxide solution in water was provided for eachtube. Each of the samples was individually packaged in a TYVEK™/MYLAR™envelope prior to sterilization.

One third of the samples (three units) were placed in the package withthe syringe unattached to the end of the tube. Another one-third of thesamples were packaged with the syringe attached. Individual samples wereplaced within a 65 liter sterilization chamber and sent through ahydrogen peroxide vapor sterilization cycle wherein the pressure withinthe chamber was reduced to 3 torr for the total exposure time minus 15minutes, and 0.5 torr for the final 15 minutes of exposure. Noadditional hydrogen peroxide was injected into the chamber.

The remaining one-third of the samples, packaged with the syringeattached to the end of the tube as described above, were sent through ahydrogen peroxide vapor sterilization cycle supplemented with highfrequency radiation plasma which is known to generate an active speciesfrom the hydrogen peroxide. Again a 65 liter chamber was used, and thepressure within the chamber was reduced to 3.0 torr for the totalexposure time minus 15 minutes and 0.5 torr for the final 15 minutes ofexposure. Again, no additional hydrogen peroxide was injected into thechamber. Plasma was generated only during the final 15 minutes ofexposure at 2.05 MHz with 320 watts of power, pulsed 0.3 milliseconds onto 1.0 milliseconds off.

At the conclusion of the sterilization cycle, the paper strip wasremoved from each tube and placed in a glass vial containing 10 ml of asterile pH 7.0 phosphate buffer solution. This solution contained 10milligrams of TWEEN 80 to aid in removal of any spores from the paperstrip and 0.0066 milligram of catalase to neutralize any remaininghydrogen peroxide. Five glass beads were placed in the solution, and thesolution was vortexed for two minutes to completely macerate the paperstrip. Three decimal dilutions of the solution were made with sterile pH7.0 phosphate buffer, and the original solution and the decimaldilutions were poured into sterile glass Petri plates. A culture mediumwas added and the plates were incubated for four days at 30° C. Afterincubation the number of viable organisms in each plate was counted, andthe number of spores on the paper strip calculated by multiplying thespore count by the appropriate dilution factor.

The results of the experiments are presented in Table I below, andplotted in FIG. 4, where S/S₀ represents the ratio of the number oforganisms surviving the test to the initial number of organisms whichwere placed on the paper strip prior to the test. As shown by thesedata, no reduction in microbial population was achieved in samples wherethe syringe was not attached to the tubing, even after an exposure timeof 75 minutes. Attaching the syringe to the end of the tube according tothe method of the present invention produced total kill in 35 minuteswithout low temperature gas plasma, and in 25 minutes when theantimicrobial activity was enhanced by the use of low temperature gasplasma.

                  TABLE I                                                         ______________________________________                                                    Sterilization                                                     Sample      Time - Min.                                                                              Efficacy (S/S.sub.0)                                   ______________________________________                                        A           35         8.6 × 10.sup.-1                                              45         8.9 × 10.sup.-1                                              75         1.1 × 10.sup.-0                                  B           20         7.0 × 10.sup.-1                                              25         5.8 × 10.sup.-1                                              35         0                                                      C           20         8.5 × 10.sup.-3                                              25         0                                                                  35         0                                                      ______________________________________                                         Sample A  Syringe unattached                                                  Sample B  Syringe attached                                                    Sample C  Syringe attached plus plasma                                   

A preferred embodiment of the device to be used in accordance with theteaching of the present invention is shown in FIG. 1. The deviceindicated generally at 10 is shown attached to a tube 12. In the devicedepicted in FIG. 1. the means for connecting the vessel 14 to the end ofthe tube comprises an expandable sheath 16, one end of which is securelyattached to the vessel, and the other end of which comprises an elasticring 18 making a releasable attachment about the end of the tube. Thesheath 16 may be attached to the vessel in any known manner and, asshown in FIG. 1, the sheath 16 is attached to the vessel by a secondelastic ring 20 disposed over the lip 22 about opening 24 of vessel 14.Though the vessel shown is cylindrical, the vessel may comprise anythree dimensional container preferably of semi-rigid material, having anopening therein. The vessel may be made of, e.g., polyethylene,polypropylene, glass or any other material which is nonreactive to theantimicrobial solution of vapor. The sheath may also be formed ofpolyethylene, polypropylene or other material which is relativelynonreactive to the antimicrobial vapor. The elastic rings may be formedof natural latex or butyl rubber which are relatively resistant to theantimicrobial vapors; however, resistivity is less critical when thedevice is constructed for one time use. Disposed within the vessel maybe a substrate 26 comprising a woven or nonwoven fabric or sponge forcontaining the liquid antimicrobial solution. The vessel preferably hasa means 28 associated with the opening for attaching a closure cap overthe opening prior to use in order to maintain the antimicrobial solutiontherein. As shown in FIG. 1, means 28 comprises threads for a screw capfitting about the lip of the vessel.

Another embodiment of the device of the present invention is depicted inFIG. 2 where the device is indicated generally at 30. The means forconnecting the vessel 34 to the end of a tubular instrument comprises abushing 36 disposed within the open end of the vessel. In the particularembodiment shown in FIG. 2, the bushing comprises a series of rings 38and 40 of inwardly extending plastic flaps defining a flexible aperture32 to receive the tubular instrument. The flaps can be made of anyflexible material which is non-reactive to the antimicrobial solution orvapor, such as polyethylene, and of sufficient thickness that the flapsprovide resistance to withdrawal of a tube inserted through theaperture. Disposed within the vessel is a substrate 42 containing theantimicrobial solution. Preferably, the vessel 34 is provided with means44 for attaching a closure cap thereto prior to use. As shown in FIG. 2,means 44 comprise threads for attaching a screw cap (not shown) withinthe opening of the vessel.

FIG. 2A illustrates a variation in the design of the device of FIG. 2which utilizes the same basic vessel and means for attachment to atubular device. In the device shown in FIG. 2A, end 45 of the vesselopposite the open end is provided with aperture 46 for attaching adisposable cartridge 47 containing a supply of antimicrobial on asubstrate such as a woven or nonwoven fabric or sponge 48 asillustrated. The aperture 46 of the vessel is designed in conjunctionwith neck 49 of the cartridge to provide quick and easy attachment andrelease of the cartridge and the vessel. In the embodiment shown in FIG.2A, aperture 46 is provided with reverse threads for engaging thethreads of the neck 49 of the cartridge. In this variation of the deviceit is not necessary for a substrate containing the antimicrobialsolution to be disposed within the vessel since the antimicrobialsolution is provided in pre-measured aliquots in the cartridges. Withthe device of FIG. 2A one achieves the convenience and accuracy ofdisposable, pre-measured aliquots of antimicrobial solution without theexpense associated with the device of FIG. 2.

The following table sets forth the effectiveness of the devices depictedin FIGS. 1 and 2 in a sterilization procedure described below.

                  TABLE II                                                        ______________________________________                                        Effect of Devices on Efficacy of Sterilization                                Inside Tubes                                                                                  Efficacy (S/S.sub.0)                                                    I. D.   Length          Device                                      Material  (cm)    (cm)    No Device                                                                             FIG. 1                                                                              FIG. 2A                               ______________________________________                                        Surgical Tygon                                                                          0.64    10      0       --    --                                              0.64    20      4.4 × 10.sup.-5                                                                 --    --                                              0.64    30      1.1 × 10.sup.-2                                                                 --    --                                              0.64    45      8.8 × 10.sup.-1                                                                 0     0                                     Rubber Tubing                                                                           0.64    25      1.7 × 10.sup.-1                                                                 --    --                                              0.64    45      7.9 × 10.sup.-1                                                                 0     0                                     ______________________________________                                    

The efficacy is recorded in terms of the ratio of the number ofmicroorganisms surviving the test, S, to the number of challengeorganisms, S₀ (approx. 1×10₆) on a paper strip disposed within the tubeequidistant from the ends. In the sterilization procedure, 100microliters of 30% aqueous H₂ O₂ solution was supplied in each of thedevices. The devices were attached to the ends of tubes of the indicatedlength and 0.64 cm in internal diameter. All of the tube samples wereplaced within TYVEK'/MYLAR' packaging prior to sterilization, Thepackaged tubes were placed within the sterilizing chamber and thepressure therein was reduced to about 0.1 torr in about 10 minutes.Additional 30% H₂ O₂ solution was injected into the chamber to achieve aconcentration of 2.0 milligrams H₂ O₂ per liter of chamber volume.Following injection of the H₂ O₂, the tubes were retained in the chamberan additional 50 minutes.

Injection of the H₂ O₂ solution raised the pressure in the chamber toabout 6 torr and the pressure was again reduced to about 0.1 torr.During the last 10 minutes of exposure, low temperature gas plasma wasgenerated in the chamber at 300 watts. The challenge micro organismsused in the test were Bacillus subtilis (var. globigii) spores.

As shown in Table II above, when the tube length was only 10centimeters, sterilization was achieved without the use of the deviceaccording to the present invention. However, for tubing of 20 and 30centimeters in length, a device of the present invention would be neededin order to achieve sterility within the exposure time of the test. Fortubes of 45 centimeters in length, total kill was achieved during the 1hour exposure time of the test, using either of the devices depicted inFIG. 1 and FIG. 2.

A further experiment used 7 mm medical grade Teflon tubing 183 cm inlength. The tubing was cut into three pieces to obtain a 5 cm longcenter section which was joined in the end sections by external tubingconnectors. In the experiment, approximately 1.0×10₄ Bacillus (var.globigii) spores were deposited in the center section of the Teflontubing. The tubing was assembled and subjected to sterilization withhydrogen peroxide vapor as described above at a concentration of 2.0mg./liter of chamber volume. The chamber was evacuated to a pressure of0.1 torr before the peroxide was injected as an aqueous solution andallowed to vaporize. After 20 minutes, a continuous gas plasma wasgenerated in the chamber at 300 watts, 13.5 MegaHertz and thesterilization continued for an additional 5 minutes after which thevacuum was released with sterile, filtered air, and the number ofsurviving spores determined.

The experiment was first conducted without a device of the presentinvention attached to the tubing, then repeated with a device of FIG. 3as described below containing 100 ml of 30% hydrogen peroxide attachedto one end of the tubing. The experimental results of the tests arepresented in Table III below.

                  TABLE III                                                       ______________________________________                                        Sterilization of 1 mm Tubing                                                  Efficacy (S/S.sub.0)                                                          Material                                                                             I.D.      Length  No Device FIG. 1 Device                              ______________________________________                                        Teflon 1 mm      183 cm  1.9 × 10.sup.-1                                                                   0                                          ______________________________________                                    

The data of Table III demonstrate the efficacy of the method of thepresent invention in sterilizing of very long tubes having very smalldiameters used in certain endoscopic procedures.

Additional embodiments of the device of the present invention aredepicted in FIGS. 3 and 3A. The device shown in FIG. 3 indicatedgenerally at 50, comprises a vessel 52 in the form of a pouchconstructed of a flexible material. The means for connecting the vesselor pouch 52 to the end of an instrument tube comprises a firstdrawstring 54, and preferably a second drawstring 62. These drawstringsare preferably arranged in the configuration as shown in FIG. 2 to bedrawn from opposite sides of the pouch. The pouch is preferably providedwith an airtight seal to maintain the antimicrobial solution thereinprior to use, and includes a means for creating an opening in the sealedpouch so that it may be disposed over the end of a tube. The seal may becreated by sealing the ends 66 of the pouch, and of the lumen as oftenthe means for opening the sealed pouch may comprise, for example, a lineof weakening at 68, preferably in combination with a notch also showngenerally at 68, to permit the pouch to be opened by tearing off oneend.

FIG. 3A shows a device indicated generally at 50A, similar to device 50,but wherein the airtight seal and the means for creating and opening thesealed pouch is a line of fastening 64 similar to a "zip-lock" closure.Optionally, opening flaps 70 may be provided on either side of the pouchadjacent closure 64 of FIG. 3A, or the line of weakening 68 of FIG. 3.These flaps are firmly secured to the pouch. In use, after the sealedend 66 of the pouch of FIG. 3 has been removed along the line ofweakening 68, the flaps when pulled oppositely from each other willdistend the opening of the pouch for disposal around the end of aninstrument tube. The flaps of FIG. 3A, when pulled in oppositedirections, can be used to open the zip-lock fastening, or if thefastening is already opened, to distend the opening for disposal aroundthe end of an instrument tube. A substrate 72 such as a woven ornonwoven fabric or sponge may be disposed within the pouch forcontaining the antimicrobial solution.

In a preferred construction, the drawstrings are provided with a lockingmeans as illustrated. Though many means for locking or catching adrawstring are known in the art and may be used in conjunction with thepresent invention, the locking means depicted at 56 at FIG. 3 comprise acatch 60 for a serrated edge 58 provided on the drawstring. As shown inFIG. 3, the catch, comprising an opening for disposing one end of thedrawstring therethrough, is located at the opposite end of thedrawstring. The catch, however, may be provided by a flap, openingtherein, attached to the edge of the pouch, provided the other end ofthe drawstring must also be attached to the pouch. When two drawstringsare used, one or both drawstrings may be provided with a locking means.By pulling the end 73 of the drawstring, the flexible pouch is gatheredand a firm fastening may be made to a tube inserted within the pouch.

Preferably, a highly concentrated solution of hydrogen peroxide is usedas the liquid antimicrobial in the device of the present invention.However, in high concentrations, hydrogen peroxide can quickly causedamage to living tissue. A system for applying such solution to aninstrument lumen while reducing the chances of accidental exposure of auser to the antimicrobial solution is highly desirable. The followingembodiments provide such advantage.

FIG. 5 illustrates a further embodiment of a device 100 according to theinvention. The device 100 comprises in gross a capsule 102, an opener104, and a safety ring 106 positioned between the capsule of 102 and theopener 104. Turning to FIG. 6, the capsule 102 comprises a cylindricalbody 108 having a distal end 110 and a proximal end 112. At the proximalend 112, the capsule body 108 expands radially to form a cup shaped well114. A membrane wall 116 is disposed within the capsule body 108adjacent to well 114.

A cap 118 of generally discoidal shape has a distally projecting annularflange 120 which fits within the well 114. The cap 118 is sonicallywelded to the capsule 102 at the proximal end 112 to seal a quantity ofantimicrobial solution 122 within a chamber 124 defined between the cap118, membrane wall 116 and capsule body 108. During storage theantimicrobial solution 122 may tend to diffuse through the capsule 102and out of the chamber 124 thereby decreasing its quantity and potency.The antimicrobial solution 122 thus preferably comprises 197 mg of 59%hydrogen peroxide solution upon construction such that after areasonable storage period such as ten months, the chamber 124 willretain approximately 100 mg of a 45% hydrogen peroxide solution.

So that it may be more easily breached, a central portion 126 of themembrane wall 116 has a slightly thinner thickness than the remainder ofthe membrane wall 116. Six radial ribs 128 extend from the capsule body108 towards, but not into, the membrane wall central portion 126 tosupport the membrane wall 116 during the breaching process.

At the capsule body distal end 110, an annular flange 130 slopesoutwardly and proximally, thus providing a barbed appearance incross-section. The distal flange 130 preferably slopes in a gentlefashion, such as a 17° slope from an imaginary coaxial centerline 132 ofthe device 100. A central annular flange 134 slopes outwardly andproximally from the capsule body 108 at a slightly more aggressive anglethan the distal flange 130. A pair of diametrically opposed slits 136extend proximally in the capsule body 108 from its distal end 110 toallow some flexibility in the capsule body 108 and to thereby ease itsentry into the opener 104.

The opener 104 comprises a cylindrical body 140 having a proximal end142 facing the capsule 102 and a distal end 144. A hollow spike 146,coaxially disposed within the opener body 146, extends toward themembrane wall 116 and terminates in a beveled and sharpened tip 148.Preferably, the tip 148 is beveled at a 30° angle from the device centerline 132. Also, a central lumen 150 extends coaxially through the spike146.

Three equilaterally spaced posts 152 extend outwardly radially from afixed end of the spike 146 to the opener body 140 and thereby supportthe spike 146 therein. Preferably, each of the posts 152 has a distallyfacing fillet brace 154 for added support. A circumferentiallyinterrupted annular embossment 156 extends radially inwardly in a veryshallow manner from the opener body 140 (see also FIG. 7). When thecapsule 102 is inserted into the opener 104 with the capsule distalflange 130 beyond the opener embossment 156, engagement therebetweenprevents the capsule 102 from being easily removed from the opener 104while still allowing a relative degree of movement between the opener104 and capsule 102 as will be more fully described hereinafter.

A retaining ring 158 holds a mist-filter screen 160 within the openerbody distal end 144. The mist-filter screen 160 is round with a diameterexceeding that of the opener body 140 whereby it is frictionallyretained within the opener body 140 by the retaining ring 158.Preferably, the mist-filter screen 160 has a mesh opening of 105 micronsand is formed of polypropylene. A plurality of axially alignedembossments 162 on an outer surface of the retaining ring 158 easeinsertion and securely retain the mist-filter screen 160 and retainingring 158 within the opener body 140 (see also FIGS. 8 and 9).

Alternatively, a series of detents (not shown), each with a distallyfacing camming surface and a proximally facing radial surface could beprovided within the opener body 140, axially adjacent the posts 152. Themist-filter screen 160 would thus have a diameter equal to the insidediameter of the opener body 140 and be held between the posts 152 andthe proximally facing surfaces of the detents. The screen could beeasily inserted through the opener distal end 144 and cammed over thedetent camming surfaces into place between the posts 152 and detents.

The safety ring 106 separates the opener 104 from the capsule 102. Withthe safety ring 106 trapped between the opener body proximal end 142 andthe lip 115 on the capsule 102, the spike 146 is prevented fromcontacting the membrane wall 116 (see also FIG. 8). The safety ring 106is provided with a thin wall section 164 and a diametrically opposedpull tab 166 whereby manual pressure applied to the pull tab 166 issufficient to deform the thin wall section 164 beyond its elastic limit,preferably breaching the thin wall section 164, thereby permittingremoval of the safety ring 106 from the device 100.

FIG. 8 illustrates the assembled device 100 prior to use, with anadapter 170 affixed thereto. The adapter 170 comprises a cylindricaltubular body 172 formed of a soft thermoplastic elastomer, such asSchafer, GmbH THEKA-FLEX, S 2030 M. A shallow inwardly facing annularflange 174 at a proximal end 176 of the adapter body 172 is receivedwithin a correspondingly shallow annular groove about the opener body140 to hold the adapter 170 to the device 100.

A truncated cone 178 extends inwardly, proximally, from a distal end 180of the adapter body 172 and terminates in a central opening 182. A luerfitting 184 of an instrument to be sterilized 186 having a lumen 188therein, is shown received within the opening 182. Those of skill in theart will appreciate that the dimensions of the cone 178 can be varied toaccommodate various types of instruments to be sterilized and that otherengaging means may be substituted therefor.

To use the device 100, an appropriately sized adapter 170 is selectedfor the particular instrument 186 to be sterilized. The adapter 170 isattached to the device 100 as shown in FIG. 8. The pull-tab 166 on thesafety ring 106 is grasped and pulled to separate the safety ring thinwall section 164 and remove the safety ring 106 from the device 100. Toaid the user in removing the safety ring 106 and in later rotating thecapsule 102 relative to the opener 104, the opener body 140 is providedwith several textured finger indentations 190 for easier grasping. Afterthe safety ring 106 is removed, the capsule 102 and opener 104 arepushed together so that the spike 146 breaches the membrane wall 116 asshown in FIG. 9. Preferably, the capsule 102 is then rotated one fullturn to ensure proper breaching of the membrane wall 116. Theantimicrobial 122 is then free to leave the chamber 124 and flow intothe instrument lumen 188.

In general practice, the device 100, with adapter 172 and instrument 186attached as the membrane wall breached 116 as shown in FIG. 9 are thenplaced into the sterilization chamber (not shown ) of a solution vaporsterilizer (also not shown). A vacuum applied to the sterilizationchamber causes the antimicrobial 122 to vaporize and migrate into theinstrument lumen 188 to effect sterilization thereof.

FIGS. 10 to 13 illustrate a further embodiment of a device 200 accordingto the invention. The device 200 is similar in nearly all respects tothe device 100 with the exception of the following differences.Accordingly, portions of the device 200 which are identical to thedevice 100 and were previously described with respect thereto, will bedesignated with like referenced numerals having a prime symbol (').

To reduce the force a user must exert to breach the membrane wall 116'the capsule 102' threads into the opener 104'. A raised embossment 202surrounds the capsule body 108' adjacent the lip 115'. A pair of threads204 formed in the embossment 202 receive, respectfully, a pair of pins206 which project into the opener body 140'. Each thread 204 comprises acamming portion 208 and a circumferential portion 210.

The pins 206 enter the threads 204 through the camming portions 208 asthe capsule 102' is rotated relative to the opener 104', thereby pullingthe capsule 102' axially into the opener 104'. The circumferentialportion 210 of the threads 204 allows the capsule 102' to be rotated anadditional one quarter turn after it is fully received within the opener104' to insure proper breaching of the membrane wall 116'.

In the previous embodiment, the interaction of the central flange 134and the opener body 140 seals the capsule 102 to the opener 104 toprevent antimicrobial 122 from leaking out of the device 100 between thecapsule 102 and opener 104. In the present embodiment, an O-ring 212about the capsule body 108' replaces the central flange 136 and engagesthe opener body 140' to seal the capsule 102' therein.

In the previous embodiment, the spike 146 is provided with a simplebevelled tip 148 to penetrate the membrane wall 116. In the presentembodiment, the bevelled tip 148 is replaced by a cutting tip 214 whichis placed off of the central axles of the spike 146' and which acts in afashion similar to that of a can opener to cut open the membrane wall116. It will be understood that the cutting tip 214 may take various

forms, however a sharp apex 216 and a sharp leading cutting edge 218improve its cutting ability.

Proper breaching of the membrane wall 116' is a prerequisite to adequatesterilization. Accordingly, operators of the devices 100 or 200 prefersome tactile, audible, visual or other feedback that the device has beenoperated properly. In the previous embodiment, breaching of the membranewall 116 tends to occur suddenly, thus driving the capsule 102 andopener 104 together in a violent manner creating both an audible andtactile snap. Also, the lip 115 will abut or closely approach thecapsule body proximal end 142 in this position to provide a visualindication of proper operation.

In the present embodiment, the threading interaction between the capsule102' and opener 104' breaches the membrane wall 116' more gently than inthe previous embodiment. Thus, the user receives less tactile feedbackthat the membrane wall 116' has been breached. It may be desirable toprovide such feedback in the form of a snapping interaction betweenparts on the capsule 102' and opener 104' or perhaps to provide a visualindication or other feedback that the opener 104' is fully actuated.

FIGS. 12 and 13 illustrate one method of providing such feedback. Aseach pins 206 travels its respective thread circumferential portion 210,it encounters a detent 220. The pins 206 cam over the detents 220 andsnap over a sharp trailing edge 222 thereon to become trapped beyond thedetents 220. Thus, the detents 220 provide both an audible and tactilefeedback that the proper interaction has been achieved between thecapsule 102' and opener 104'. Further, they prevent the capsule 102' andopener 104', and further prevent the capsule 102' from being easilybacked out of the opener 104'. Alignment marks (not shown) or othervisual indicia mark also be provided on the capsule 102' and opener 104'to indicate full actuation.

Although the present invention has been described in terms of specificdevices for use in a preferred method of vapor sterilization, it will beunderstood that various modifications in the device and method will beapparent to those skilled in the art and are within the scope of thisinvention.

What is claimed is:
 1. A device for delivering an antimicrobial vapor toa lumen of an article during solution vapor sterilization, the devicecomprising:a first member comprising a vessel having an inner sealedchamber containing an antimicrobial solution and a wall forming at leasta portion of the chamber; a connector in communication with the wall forconnecting the vessel to the article lumen; a second member connected tothe first member in moveable relation thereto, the second membercomprising an opening member whereby movement of the second member in apredetermined direction relative to the first member moves the openingmember toward wall to open the wall and place the chamber into fluidcommunication with the article lumen; wherein the chamber containing theantimicrobial solution may be opened and placed into communication withthe article lumen with the connector connected to the article lumenwhereby a user is thereby isolated from the antimicrobial solutionduring a process of opening the chamber.
 2. A device according to claim1 and further comprising a first abutting surface on the first member, asecond abutting surface on the second member and a removable guardbetween the first and second abutting surfaces wherein the removableguard prevents the first and second members from moving togethersufficiently to breach the wall.
 3. A device according to claim 2wherein the guard further comprises a contrasting appearance to thefirst and second members whereby the presence or absence of the guardcan easily be visually determined.
 4. A device according to claim 2wherein the guard comprises a ring encircling the device between thefirst and second members.
 5. A device according to claim 4 wherein thering is inelastic whereby to remove the ring from between the first andsecond abutting surfaces it must be deformed beyond its elastic limit.6. A device according to claim 1 wherein the opening member comprises apenetrating member for penetrating the wall.
 7. A device according toclaim 6 wherein the penetrating member comprises a spike having a firstend which faces the wall and comprises a sharpened tip.
 8. A deviceaccording to claim 7 wherein the spike further comprises a second endand a central lumen extending coaxially therethrough, the spike lumenhaving a first end at the first end of the spike and a second end, thesecond end of the spike lumen being in fluid communication with theconnector whereby the vessel is placed into fluid communication with thearticle lumen through the spike lumen when the spike penetrates thewall.
 9. A device according to claim 8 and further comprising a passagefor the antimicrobial solution from the chamber to the connectorexterior of spike lumen.
 10. A device according to claim 9 wherein thesecond member is tubular and has an inner wall, the first and secondmembers are disposed in telescoping relation to one another and thespike is supported within the second member by at least one postextending from the second member inner wall wherein the spike is spacedtherefrom to form the passage exterior of the spike lumen.
 11. A deviceaccording to claim 1 wherein the first and second members areinterconnected in telescoping relationship with each other.
 12. A deviceaccording to claim 11 and further comprising a first detent extendingfrom one of the first and second members and a first surface extendingfrom the other of the first and second members, the first detentengaging the first surface to limit the degree to which the first andsecond members can telescope apart, wherein the other of the first andsecond members is free from obstructions such that the first and secondmembers can move from a position with the first detent and first surfaceengaged to a position wherein the opening member contacts the wallwithout interference with each other.
 13. A device according to claim 11wherein one of the first and second members comprises a projection andthe other of the first and second members is tubular and telescopicallyreceive the projection therein.
 14. A device according to claim 11wherein the second member is tubular and wherein a projection on thefirst member extends axially from adjacent the wall and istelescopically received within the second member.
 15. A device accordingto claim 14 wherein the connector is disposed at the proximal end of thesecond member whereby the vessel can be placed into fluid communicationwith the article lumen through the tubular second member and through theconnector.
 16. A device according to claim 14 and further comprising amist filter in the second member between the first member and theconnector to prevent liquid antimicrobial solution or contaminants fromentering the article lumen.
 17. A device according to claim 14 whereinthe opening member comprises a spike received within the second memberin a position to breach the wall when the first and second members aretelescoped together.
 18. A device according to claim 17 wherein thespike further comprises a first end facing the wall, a second end and acentral lumen extending coaxially therethrough, the spike lumen having afirst end at the first end of the spike and a second end, the second endof the spike lumen being in fluid communication with the connectorwhereby the vessel is placed into fluid communication with the articlelumen through the spike lumen when the spike penetrates the wall.
 19. Adevice according to claim 18 and further comprising a first abuttingsurface on the first member, a second abutting surface on the secondmember and a removable guard between the first and second abuttingsurfaces wherein the removable guard prevents the first and secondmembers from moving together sufficiently to breach the wall.
 20. Adevice according to claim 14 and further comprising a threadedinterconnection between the first and second members wherein rotation ofthe first and second members relative to each other moves them togetherto breach the wall.
 21. A device according to claim 20 wherein thedevice further comprises a sharp leading cutting edge on the spike whichis positioned so that when the first and second members are rotatedtogether, the cutting edge cuts through the wall.
 22. A device accordingto claim 20 and further comprising a tactile detent on one of the firstand second members positioned to engage a tactile detent engagingsurface on the other of the first and second members as the first andsecond members are rotated together whereby the interaction of thetactile detent and the tactile detent engaging surface produces atactile feedback to a user that the first and second members are fullyrotated together.
 23. A device according to claim 20 wherein theprojection comprises a thread, the second member comprises a threadengaging protuberance and wherein the tactile detent is disposed withinthe thread and wherein the tactile detent engaging surface comprises thethread engaging protuberance.